98 S10 Blazer

The RPM’s startes jumping going down the road (about 5 sec.) then it would be fine. Sometimes it would do it a couple its a day maybe not for a week. Then one day. Then while stopped at a stop sign it did it. Pushing me out into traffic (thank god no cars coming). It did die. Got it started took it back home. Had a scanner put on it. It said I had misfires. I replaced the cap & roter. I havent drove it yet cause now the speedometer andtackometer wont work and I cant the P.R.N.D.1.2.3 and the odometer wont light up. Check the fuses but not relays. Thank you for your time

Check underhood fuses as well as interior fuse box. If no joy unplug music radio and see if instrument panel now starts working.

Your symptoms are about more than just misfires. So while you probably are misfiring you likely have more troubles than that - and even some that might be causing the misfiring.

Were there any other error codes? If so report the specific code number (e.g. “P0123”). What were the specific misfire codes?

How many miles are on it? How old are the spark plugs and wires? Filters? Has the transmission ever been serviced? After checking all of the fuses and stuff I would want to have the alternator tested as it can make all sorts of things go wonky. You pretty much need to go over all of the basics - system voltage; check for vacuum leaks; check fuel pressure; plugs/wires etc.

My auto-mechanic is the one that ran the scan. He started replacing parts as fast as he could.Then everytime he would run another scan it would read something else. Miles I dont recall and I cant see it. Spark plugs dont know. Oil change and filter like clock work